1. Preheat your oven's broiler.
2. Slice grapefruit in half and place cut side up on a cookie sheet.
3. Lightly sprinkle with cinnamon.
4. Broil 4-6 minutes, or until top of grapefruit appears caramelized and slightly golden.
5. Enjoy warm.
Heating the grapefruit brings out the natural sugars and softens the grapefruit. Now it's easier to eat and sweeter!